20 POINTS + BRAINLIEST, HELP

Answer:

a. aluminum

Explanation:

Given electronic configuration:

       1s² 2s² 2p⁶ 3s² 3p¹  

The number of electrons can be determined from adding the powers or superscripts.

Since we are dealing with a neutral element, the number of electrons and protons are the same. So we can determine the atomic number which is the number of protons.

Number of electrons  = 2 + 2 + 6 + 2 + 1  = 13

The element with atomic number 13 is aluminum.

The given electronic configuration adds up to 13 which is the atomic number of aluminium.Thus, the correct option is A.

Electronic configuration is defined as the distribution of electrons which are present in an atom or molecule in atomic or molecular orbitals.It describes how each electron moves independently in an orbital.

Knowledge of electronic configuration is necessary for understanding the structure of periodic table.It helps in understanding the chemical properties of elements.

Elements undergo chemical reactions in order to achieve stability. Main group elements obey the octet rule in their electronic configuration while the transition elements follow the 18 electron rule. Noble elements have valence shell complete in ground state and hence are said to be stable. Aluminium has the given electronic configuration.

Thus, the correct option is A.

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Answer:

0.83 bar

That is

23/300*100

=0.83 bar

Answer:

The answer is "Option b, c, and d".

Explanation:

In such a gene, Autosomes are also the sequence for code and transposable elements, not the series of encoding. Through the expression of genes, such fragments of its introns are split through protein complexes throughout the translation process. There has been no kenaf fiber in the genomes of prokaryotic cells.

Answer:

0.35 M

Explanation:

Using the formula; C1V1 = C2V2

Where;

C1 = concentration of initial solution

C2 = concentration of final solution

V1 = volume of initial solution

V2 = volume of final solution

Based on this question, I start with 0.0350 L of a 12.0 M hydrochloric acid solution, and dilute it with water to a new volume of 1.20 L. This means that:

C1 = 12.0 M, V1 = 0.0350 L, V2 = 1.20 L, C2 = ?

Hence, C1V1 = C2V2

12 × 0.0350 = C2 × 1.20

0.42 = 1.2C2

C2 = 0.42/1.2

C2 = 0.35 M

Answer:

you cant post pictures on brainly answers.... can you?

Explanation:

Answer:

44.8g

Explanation:

The reaction equation is given as:

        4Fe + 3O₂  →  2Fe₂O₃

Given:

Mass of O₂   = 19.2g

Unknown:

Amount of iron used  =?

Solution:

To solve this problem, we adopt the mole concept.

   Since we know the mass of O₂;

         Number of moles  = [tex]\frac{mass}{molar mass}[/tex]  

 Molar mass of  O₂ = 2(16)  = 32g/mol

           Number of moles = [tex]\frac{19.2}{32}[/tex]   = 0.6moles

From the balanced reaction equation;

           4 moles of Fe will react with 3 moles of O₂

          0.6moles of O₂ will react with [tex]\frac{0.6 x 4}{3}[/tex]   = 0.8mole of Fe

Mass of Fe  = number of moles x molar mass

                    = 0.8 x 56

                     = 44.8g

Answer:

1.43 (w/w %)

Explanation:

HCl reacts with NH3 as follows:

HCl + NH3 → NH4+ + Cl-

1 mole of HCl reacts per mole of ammonia.

Mass of NH3 is obtained as follows:

Moles HCl:

0.02999L * (0.1068mol / L) = 3.203x10-3 moles HCl = Moles NH3

Mass NH3 in the aliquot:

3.203x10-3 moles NH3 * (17.031g / mol) = 0.0545g.

Mass of sample + water = 22.225g + 75.815g = 98.04g

Dilution factor: 98.04g / 14.842g = 6.6056

That means mass of NH3 in the sample is:

0.0545g * 6.6056 = 0.36g NH3

Weight percent is:

0.36g NH3 / 25.225g * 100

Answer:mnedd kfj

Explanation:

fr rb r

Answer:

Yes!

Explanation:

I think It would be fun!, Going thought space going from planet to planet. once i get back to earth i can make a document about my time in space.

Answer:

Not sure if you just wanted the basic structure or full on structure.

Explanation:

Answer:

sulfide ion

Explanation:

however, when non-metalic elements gain electrons to form anions the end of their name is change to "-ide".foe example, a flourin atom gains one electronto become a flouride ion(F`) and sulfur gains two electrons to become a sulfide ion(s^2)

Answer:

Adding heat to the reaction or increasing pressure

Explanation:

Increasing temperature or pressure will result in chemical reaction rates to speed up.

Answer:

T(final) = 52°C

Explanation:

1st, you need to correct your heat flow formula => q = mcΔT.

m = 22.5g

c = 0.45 j/g·°C

ΔT = T(final) - T(initial) = T(final) - 20°C

q = (22.5g)(0.45j/g·°C)((final) - 20°C) = 324j

=> T(final) = [324j/(22.5g)(0.45j/g·°C)] + 20°C = 52°C

Liquid 2 because the lower the density the more it floats and the higher the density the more it sinks. The order from top to bottom is liquid 2, liquid 3, liquid 1

To calculate the atoms of an element in a given molecule, we need to multiply stoichiometry by the number that is written on the foot of that element. Therefore, the products are carbon dioxide, sulfur dioxide and water.

Balanced equation is the one in which the total number of atoms of a species on reactant side is equal to the total number of atoms on product side. The mass of the overall reaction should be conserved. There are so many types of chemical reaction reaction like combination reaction, displacement reaction.

The other characteristic of balanced equation is that physical state should be written with each compound or molecule on reactant and product side. Physical state should be written in brackets. s means solid, l means liquid, g means gas.

The balanced equation is

CH[tex]_3[/tex]SH + 4O[tex]_2[/tex] → CO[tex]_2[/tex] + SO[tex]_2[/tex] +2H[tex]_2[/tex]O

The products that are formed in the given reaction are carbon dioxide, sulfur dioxide and water.

Therefore, the products are carbon dioxide, sulfur dioxide and water.

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Answer:

answer is d Combining

Explanation:

I did the test and got it correct

As a chemical change takes place when binders are added to a paint mixture combining part of the manufacturing process occurs.

Chemical changes are defined as changes which occur when a substance combines with another substance to form a new substance.Alternatively, when a substance breaks down or decomposes to give new substances it is also considered to be a chemical change.

There are several characteristics of chemical changes like change in color, change in state , change in odor and change in composition . During chemical change there is also formation of precipitate an insoluble mass of substance or even evolution of gases.

There are three types of chemical changes:

1) inorganic changes

2)organic changes

3) biochemical changes

During chemical changes atoms are rearranged and changes are accompanied by an energy change as new substances are formed.

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Answer:

A: COAL

Explanation:

Coal was created hundreds of millions years ago. When prehistoric plant life died and sank to the bottom of the swamp and was covered by layers of sediment.

Answer:

i just took the test the correct answer is   "most of them stay green all year"

Explanation:

Answer:

its B :)

Explanation:

cuz im mr beast

Answer:

[H₃O⁺] = 0.0507 M

pH = 1.29

Explanation:

23.1 g of HCI (a strong acid) is added to water to make 1250 mL of solution. Calculate [H₃O⁺] and pH of the solution.

Step 1: Given data

Step 2: Calculate the concentration of HCl

We will use the following expression.

[HCl] = mass HCl / molar mass HCl × liters of solution

[HCl] = 2.31 g / 36.46 g/mol × 1.250 L

[HCl] = 0.0507 M

Step 3: Calculate the concentration of H₃O⁺

HCl is a strong acid according to the following equation.

HCl(aq) + H₂O(l) ⇒ H₃O⁺(aq) + Cl⁻(aq)

The molar ratio of HCl to H₃O⁺ is 1:1. Then, [H₃O⁺] = 0.0507 M.

Step 4: Calculate the pH of the solution

We will use the following expression.

pH = -log [H₃O⁺]

pH = -log 0.0507

pH = 1.29

a.NH₃+HCl⇒NH₄Cl

b.volume HCl=150 ml

c. pH=4.82

Reaction

NH₃+HCl⇒NH₄Cl

The equivalence point⇒mol NH₃=HCl

Titration formula :

M₁V₁n₁=M₂V₂n₂(n=acid base valence, NH₃=HCl=1)

mol NH₃

[tex]\tt 2.5\times 30=75~mlmol[/tex]

mol HCl=75 mlmol

[tex]\tt \dfrac{75}{0.5}=150~ml[/tex]

Volume total :

[tex]\tt 150+30=180~ml[/tex]

mol NH₄Cl=mol NH₃=75 mlmol=0.075 mol

[tex]\tt M=\dfrac{0.075}{0.180}= 0.42[/tex]

Dissociation of NH₄Cl at water to find [H₃O⁺]

[tex]\tt NH_4+H_2O\rightarrow NH_3+H_3O^+[/tex]

ICE at equilibrium :

0.41-x            x        x

Ka(Kw:Kb)= 10⁻¹⁴ : 1.8.10⁻⁵=5.6.10⁻¹⁰

[tex]\tt Ka=\dfrac{NH_3.H_3O}{NH_4}=\dfrac{x^2}{0.41}[/tex]

[H₃O⁺]=x :

[tex]\tt \sqrt{5.6.10^{-10}\times 0.41}=1.515.10^{-5}[/tex]

pH=-log[H₃O⁺]

[tex]\tt pH=5-log~1.515=4.82[/tex]

Answer:

In chemistry, a single bond is a chemical bond between two atoms involving two valence electrons. That is, the atoms share one pair of electrons where the bond forms. Therefore, a single bond is a type of covalent bond.

Explanation:

(copied from Google)

Answer:a a atom

Explanation:

Answer:

a. carbon

b. atomic number

c. mass number

d. 6

e. 7

f. 8

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Answer:

be.77.0kj.

Explanation:

add moles then times

Considering the definition of enthalpy of vaporization,  the correct answer is option c. the heat required to vaporize 15.8 g of CH₃OH at its boiling point is 18.8 kJ.

When a material changes phase from solid to liquid, or from liquid to gas, a certain amount of energy is involved in this phase change.

In case of phase change from liquid to gas, this amount of energy is known as enthalpy of vaporization (symbolized as ∆H vap), also known as (latent) heat of vaporization or heat of evaporation.

In other words, the enthalpy of vaporization is the amount of energy required to change a unit of mass (for example, moles or kg) of a substance from phase liquid to phase gas at constant temperature and pressure.

In this case, you know that enthalpy of vaporization is ∆Hvap = 38.0 kJ/mol.

On the other side, you want to vaporize 15.8 g of CH₃OH.  Then, being the molar mass of the compound 32 g / mole (that is, the amount of mass contained in one mole), the number of moles to be vaporized is:

[tex]15.8 gramsx\frac{1 mol}{32 grams}= 0.49375 moles[/tex]

Then, the heat required to vaporize 0.49375 moles of CH₃OH at its boiling point is calculated taking into account the enthalpy of vaporization by:

0.49375 moles×  38.0 kJ/mol= 18.76 kJ ≅ 18.8 kJ

Finally, the correct answer is option c. the heat required to vaporize 15.8 g of CH₃OH at its boiling point is 18.8 kJ.

Learn more:

Answer:

C

Explanation:

The net reaction  after canceling common terms should be considered as the autoionization of water.

Since acids and bases should be react with each other, this shows that water could be react with itself. Here the sound should be stranged. Also, the water molecules should be exchanged the protons to the small extent.

hence, The net reaction  after canceling common terms should be considered as the autoionization of water.

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Answer:

If two atoms have different numbers of protons, they are different elements. However, if two atoms have the same number of protons, but different numbers of neutrons we refer to them as isotopes. Two terms we use to identify nuclides (isotopes) are atomic number and mass number.

Explanation:

Your Welcome!

To see the number of atoms of an element in a given molecule we need to multiply stoichiometry to the number that is written on the foot of the element that is stoichiometry. Therefore, in below given ways we can identify isotopes.

Atom is the smallest particle of any element, molecule or compound. Atom can not be further divided. Atoms contains nucleus in its center and electron that revolve around the atom in fixed orbit.

In the nucleus, proton and neutron are present. Electron has -1 charge while proton has +1 charge. Neutron is neutral that is it has no charge. So overall the charge of nucleus is due to only proton, not by neutron.

Differing elements exist when two atoms contain different numbers of protons. If two atoms contain the same amount of protons but differing numbers of neutrons, they are referred to be isotopes.

Therefore, in above given ways we can identify isotopes.

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